Meta-Analysis Comparing Apixaban Versus Rivaroxaban for Management of Patients With Nonvalvular Atrial Fibrillation.

To compare the efficacy and safety of apixaban and rivaroxaban for the prevention of stroke in patients with nonvalvular atrial fibrillation (NVAF) by way of a meta-analysis informed by real-world evidence. Systematic review and meta-analysis of observational studies including patients with NVAF on apixaban and rivaroxaban, which reported stroke/systemic embolism and/or major bleeding. Prospero registration number: CRD42021251719. Estimates of relative treatment effect (based on hazard ratios[HRs]) were pooled using the inverse variance method. Fixed-effects and random effect analyses were conducted. Exploratory meta-regression analyses that included study-level covariates were conducted using the metareg (meta-regression) command of Stata Statistical Software: Release 15.1 (College Station, Texas. StataCorp LLC.). Study level covariates explored in the meta-regression analyses were CHA2DS2-VASc and HAS-BLED scores. A total of 10 unique retrospective real-world evidence studies reported comparative estimates for apixaban versus rivaroxaban in patients with NVAF and were included in the meta-analysis. Adjusted HR was 0.88 (95% [confidence interval] CI 0.81 to 0.95), indicating a significantly lower hazard of stroke/systemic embolism associated with apixaban versus rivaroxaban. Pairwise meta-analysis for a major bleeding episode was significantly lower with apixaban compared with rivaroxaban (HR 0.62; 95% CI 0.56 to 0.69), whereas apixaban was associated with a lower risk of gastrointestinal bleeding compared with rivaroxaban (HR 0.57; 95% CI 0.50 to 0.64). In conclusion, this study suggests that patient CHA2DS2-VASc and HAS-BLED scores might be an important factor when selecting which direct oral anticoagulants to use, given the relation these scores have on treatment outcomes. Apixaban is associated with lower rates of both major and gastrointestinal bleeding than rivaroxaban, with no loss of efficacy.

Automation of in-hospital pharmacy dispensing: a systematic review.

OBJECTIVES: The current systematic review (SR) was undertaken to identify and summarise the published literature reporting on the clinical and economic value of automated in-hospital pharmacy services with a primary focus on systems supporting the dispensing of medicines. METHODS: Literature searches were conducted in MEDLINE, Embase and the Cochrane Library on 17 December 2017 to identify English-language publications investigating any automated dispensing systems (ADSs) in the inpatient setting to include central pharmacy and ward-based systems. RESULTS: 4320 publications were screened by title and abstract and 45 of 175 full publications screened were included. Grey literature searching identified an additional three publications. Therefore, 48 publications relating to ADSs were eligible for inclusion. Although a relatively large evidence base was identified as part of the current SR, the eligible studies were inconsistent in terms of their design and the format of reporting of outcomes. The studies demonstrate that both pharmacy and ward-based ADSs offer benefits over traditional manual dispensing methods in terms of clinical and economic outcomes. The primary benefits following implementation of an ADS include reductions in medication errors, medication administration time and costs. Studies examining optimisation/inventory management strategies/refill programmes for these systems suggest that optimal implementation of the ADS is required to ensure that clinical success and economic benefits are maximised. CONCLUSIONS: The published evidence suggests positive impacts of ADS and should encourage hospitals to invest in automation, with a global strategy to improve the reliability and the efficiency of the medication process. However, one of the key findings of the current SR is the need for further data from adequately powered studies reporting clinically relevant outcomes which would allow for robust, evidence-based recommendations on the return on investment of the technologies. These studies would probably contribute to a larger adoption of these technologies by European hospitals.

Automated compounding technology and workflow solutions for the preparation of chemotherapy: a systematic review.

OBJECTIVES: The current systematic review (SR) was undertaken to summarise the published literature reporting the clinical and economic value of automation for chemotherapy preparation management to include compounding workflow software and robotic compounding systems. METHODS: Literature searches were conducted in MEDLINE, Embase and the Cochrane Library on 16 November 2017 to identify publications investigating chemotherapy compounding workflow software solutions used in a hospital pharmacy for the preparation of chemotherapy. RESULTS: 5175 publications were screened by title and abstract and 18 of 72 full publications screened were included. Grey literature searching identified an additional seven publications. The SR identified 25 publications relating to commercial technologies for compounding (Robotic compounding systems: APOTECAchemo (n=12), CytoCare (n=5) and RIVA (n=1); Workflow software: Cato (n=6) and Diana (n=1)). The studies demonstrate that compounding technologies improved accuracy in dose preparations and reduced dose errors compared with manual compounding. Comparable levels of contamination were reported for technologies compared with manual compounding. The compounding technologies were associated with reductions in annual costs compared with manual compounding, but the impact on compounding times was not consistent and was dependent on the type of compounding technology. CONCLUSIONS: The published evidence suggests that the implementation of chemotherapy compounding automation solutions may reduce compounding errors and reduce costs; however, this is highly variable depending on the form of automation. In addition, the available evidence is heterogeneous, sparse and inconsistently reported. A key finding from the current SR is a 'call to action' to encourage pharmacists to publish data following implementation of chemotherapy compounding technologies in their hospital, which would allow for evidence-based recommendations on the benefits of chemotherapy compounding technologies.

A Systematic Literature Review of Economic Evaluations of Antibiotic Treatments for Clostridium difficile Infection.

BACKGROUND AND OBJECTIVE: Clostridium difficile infection (CDI) is associated with high management costs, particularly in recurrent cases. Fidaxomicin treatment results in lower recurrence rates than vancomycin and metronidazole, but has higher acquisition costs in Europe and the USA. This systematic literature review summarises economic evaluations (EEs) of fidaxomicin, vancomycin and metronidazole for treatment of CDI. METHODS: Electronic databases (MEDLINE®, Embase, Cochrane Library) and conference proceedings (ISPOR, ECCMID, ICAAC and IDWeek) were searched for publications reporting EEs of fidaxomicin, vancomycin and/or metronidazole in the treatment of CDI. Reference bibliographies of identified manuscripts were also reviewed. Cost-effectiveness was evaluated according to the overall population of patients with CDI, as well as in subgroups with severe CDI or recurrent CDI, or those at higher risk of recurrence or mortality. RESULTS: Overall, 27 relevant EEs, conducted from the perspective of 12 different countries, were identified. Fidaxomicin was cost-effective versus vancomycin and/or metronidazole in 14 of 24 EEs (58.3%), vancomycin was cost-effective versus fidaxomicin and/or metronidazole in five of 27 EEs (18.5%) and metronidazole was cost-effective versus fidaxomicin and/or vancomycin in two of 13 EEs (15.4%). Fidaxomicin was cost-effective versus vancomycin in most of the EEs evaluating specific patient subgroups. Key cost-effectiveness drivers were cure rate, recurrence rate, time horizon, drug costs and length and cost of hospitalisation. CONCLUSIONS: In most EEs, fidaxomicin was demonstrated to be cost-effective versus metronidazole and vancomycin in patients with CDI. These results have relevance to clinical practice, given the high budgetary impact of managing CDI and increasing restrictions on healthcare budgets. OTHER: This analysis was initiated and funded by Astellas Pharma Inc.

Tyrosine kinase inhibitor combination therapy in first-line treatment of non-small-cell lung cancer: systematic review and network meta-analysis.

INTRODUCTION: The introduction of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has improved the outlook for patients with advanced non-small-cell lung cancer (NSCLC) with EGFR+ mutations. However, most patients develop resistance, with the result that median progression-free survival (PFS) is12 months. Combining EGFR-TKIs with other agents, such as bevacizumab, is a promising approach to prolonging remission. This systematic review and network meta-analysis (NMA) were undertaken to assess available evidence regarding the benefits of first-line combination therapy involving EGFR-TKIs in patients with advanced NSCLC. METHODS: Literature searches were performed using relevant search terms. Study-level pseudo-individual patient-level data (IPD) were recreated from digitized Kaplan-Meier curve data, using a published algorithm. Study IPD were analyzed using both the proportional hazards and the acceleration failure time (AFT) survival models, and it was concluded that the AFT model was most appropriate. An NMA was performed based on acceleration factors (AFs) using a Bayesian framework to compare EGFR-TKIs and chemotherapy. RESULTS: Nine randomized controlled trials were identified that provided data for EGFR-TKI therapy in patients with EGFR+ tumors. These included studies of afatinib (n=3), erlotinib (n=3), erlotinib plus bevacizumab (n=1) and gefitinib (n=2). Erlotinib plus bevacizumab produced the greatest increase in PFS compared with chemotherapy, with 1/AF being 0.24 (95% credible interval [CrI] 0.17, 0.34). This combination also produced greater increases in PFS compared with EGFR-TKI monotherapy: 1/AF versus afatinib, 0.51 (95% CrI 0.35, 0.73); versus erlotinib, 0.53 (95% CrI 0.39, 0.72) and versus gefitinib, 0.46 (95% CrI 0.32, 0.66). All three EGFR-TKI monotherapies prolonged PFS compared with chemotherapy; estimates of treatment effect ranged from 1/AF 0.53 (95% CrI 0.48, 0.60) for gefitinib to 1/AF 0.46 (95% CrI 0.40, 0.53) for erlotinib. There was no evidence for differences between EGFR-TKI monotherapies, as all 95% CrIs included the null value. CONCLUSION: Although data for erlotinib plus bevacizumab came from a single Phase 2 study, the results of the NMA suggest that adding bevacizumab to erlotinib may be a promising approach to improving the outcomes achieved with EGFR-TKI monotherapy in patients with advanced EGFR+ NSCLC.

Relative efficacy and safety of non-Vitamin K oral anticoagulants for non-valvular atrial fibrillation: Network meta-analysis comparing apixaban, dabigatran, rivaroxaban and edoxaban in three patient subgroups.

BACKGROUND: Stroke is the most serious clinical consequence of atrial fibrillation, which is the most common cardiac arrhythmia. Non-vitamin K antagonist oral anticoagulants (NOACs) have emerged as efficacious, safe and convenient stroke prevention agents. This updated network meta-analysis focused on the relative efficacy and safety of apixaban compared with dabigatran, rivaroxaban and edoxaban for stroke prevention in (i) patients with CHADS2 score ≥ 2, (ii) secondary stroke prevention, and (iii) patients with high quality anticoagulation control with warfarin. METHODS AND RESULTS: A fixed-effects network meta-analysis was conducted, including data from four Phase III randomised controlled trials (> 70,000 patients with non-valvular atrial fibrillation). The results of the base-case analysis comparing NOACs with warfarin were broadly in line with the results from the individual trials. Results from the three subgroup analyses were broadly similar to the base case results. For example in patients with CHADS2 score ≥ 2, apixaban, high-dose dabigatran, rivaroxaban, and high-dose edoxaban had significantly lower hazards of stroke/systemic embolism compared with low-dose edoxaban. Apixaban and low-dose edoxaban were associated with significantly lower hazards of major bleeding compared with rivaroxaban and dabigatran 150 mg. However, several treatment comparisons that were significant in the base-case analysis were not significant in the patient subgroups, due to the reduced sample size of the subgroups compared with the overall population. CONCLUSIONS: Among the NOACs, apixaban offered the most favourable efficacy and safety profile in the overall patient population as well as in the three subgroups investigated.

Health state utility values associated with advanced gastric, oesophageal, or gastro-oesophageal junction adenocarcinoma: a systematic review.

OBJECTIVES: To systematically identify utility values associated with advanced gastric cancer (GC), oesophageal cancer (OC), or gastro-oesophageal junction (GEJ) cancer. Utility values relating to health states are an essential component for cost-utility analysis (CUA). METHODS: MEDLINE, Embase, Cochrane Library, and EconLit databases were reviewed for relevant studies using a pre-defined search strategy. Studies eligible for inclusion reported health state utility values (HSUVs) using direct (standard gamble [SG] and time-trade-off [TTO]) and indirect (such as EuroQol 5D [EQ-5D], short-form 6D [SF-6D], and the 15-dimensional instrument [15D]) methods for patients with advanced GC, OC, or GEJ cancer. RESULTS: A total of 539 unique publications were identified, of which eight met the inclusion criteria (GC, n = 2; mixed population [gastrointestinal cancers], n = 4; OC, n = ). The most commonly used instrument to estimate HSUVs was the EQ-5D (n = 7). Utilities were also estimated using the SF-6D and the 15D in the same study (n = 1). Direct elicitation methods included the TTO (n = 2) and SG (n = 1). Across the eight identified publications, health states and study populations were heterogeneous and sample sizes were limited. LIMITATIONS: This review, as with all summaries of this nature, is only as robust as the data derived from the identified studies. The systematic review process does not resolve any design issues or biases associated with the original studies. CONCLUSIONS: Limited data estimate HSUVs in patients with advanced GC, OC, or GEJ cancer. Utilities for advanced GC alone and advanced OC alone were reported in only two publications for each cancer type. No publications considered advanced GEJ utilities alone, and four publications considered utilities for a mixed population of gastrointestinal cancer types. Comparisons are confounded by heterogeneity across the identified publications. Further research into HSUVs associated with advanced GC and OC is required to improve the evidence available for use in CUAs.

Mitral regurgitation - Unmet need for improved management strategies.

BACKGROUND: The management of mitral regurgitation (MR) is challenging - patients may be asymptomatic, oligosymptomatic, older with comorbidities, or clinically symptomatic and not appropriate for surgery. The current review assesses morbidity, mortality, and risk factors associated with functional and organic MR, with a focus on severe MR. METHODS: A structured literature review was conducted in MEDLINE, Embase, the Cochrane Library, and via hand-searching of conference proceedings. Prospective randomised controlled trials and observational studies including adult patients with MR reporting on treatment response rates, survival, time-to-treatment failure, quality of life, and adverse events were eligible for inclusion. RESULTS: In total, 32 publications met the inclusion criteria (9 in functional, 18 in organic, and 5 in functional/organic). Despite study heterogeneity, an increased risk of mortality and morbidity was observed which increased with MR severity. Risk factors associated with mortality and morbidity included advancing age, presence of atrial fibrillation, increasing effective regurgitant orifice, ejection fraction, left ventricle end systolic diameter, diabetes, and increasing New York Heart Association class. CONCLUSIONS: The current review represents one of the most comprehensive conducted in the medical/conservative management of MR. An increased risk of mortality and morbidity, which appeared to rise with greater severity, was associated with MR (versus no MR). An unmet need exists in the management of patients with severe symptomatic MR and a high surgical risk as they have a poor prognosis and limited treatment options. Further research into alternative medical strategies and patient management is needed to improve prognoses and reduce mortality and morbidity.

The radiation of cynodonts and the ground plan of mammalian morphological diversity.

Cynodont therapsids diversified extensively after the Permo-Triassic mass extinction event, and gave rise to mammals in the Jurassic. We use an enlarged and revised dataset of discrete skeletal characters to build a new phylogeny for all main cynodont clades from the Late Permian to the Early Jurassic, and we analyse models of morphological diversification in the group. Basal taxa and epicynodonts are paraphyletic relative to eucynodonts, and the latter are divided into cynognathians and probainognathians, with tritylodonts and mammals forming sister groups. Disparity analyses reveal a heterogeneous distribution of cynodonts in a morphospace derived from cladistic characters. Pairwise morphological distances are weakly correlated with phylogenetic distances. Comparisons of disparity by groups and through time are non-significant, especially after the data are rarefied. A disparity peak occurs in the Early/Middle Triassic, after which period the mean disparity fluctuates little. Cynognathians were characterized by high evolutionary rates and high diversity early in their history, whereas probainognathian rates were low. Community structure may have been instrumental in imposing different rates on the two clades.

The efficacy and safety of oral anticoagulants in warfarin-suitable patients with nonvalvular atrial fibrillation: systematic review and meta-analysis.

The novel oral anticoagulants (NOACs) apixaban, dabigatran, and rivaroxaban have been recently indicated for stroke prevention in patients with atrial fibrillation (AF) . Due to a lack of direct head-to-head trials comparing the NOACs, the current systematic review and network meta-analysis (NMA) were conducted to assess their relative efficacy and safety. Three phase III randomized controlled trials enrolling 50 578 patients were included. Results of the NMA show a clear trend favoring NOACs over warfarin with regard to the key outcomes of stroke/systemic embolism and all-cause mortality, with apixaban also showing a favorable response for major bleeding and total discontinuations. Although there were few significant differences among the NOACS with regard to efficacy outcomes, apixaban and dabigatran 110 mg were associated with significantly lower hazards of major bleeding compared with dabigatran 150 mg and rivaroxaban. The NOACs offer a therapeutic advance over standard warfarin treatment in stoke prevention in patients with nonvalvular AF.

Interventions for the treatment of atrial fibrillation: a systematic literature review and meta-analysis.

BACKGROUND: To perform a systematic review/meta-analysis evaluating the efficacy and safety of anti-arrhythmic drugs (AADs) in the treatment of atrial fibrillation (AF). METHODS: Database searches (accessed April 2009) were conducted to identify randomised controlled trials (RCTs). Comparators of interest included all AADs, rate/rhythm strategies or catheter ablation in comparison with AADs. Primary AADs of interest were restricted to Class IC (flecainide and propafenone) and Class III (amiodarone, dofetilide, dronedarone and sotalol). Data were analysed on an intention-to-treat basis and meta-analysis performed using the Peto odds ratio (OR)/fixed-effect model. RESULTS: 113 publications met inclusion criteria. Of these, 74 publications considered an AAD of primary interest. The odds of AF recurrence were generally significantly lower with all active treatments versus non-active control. Dronedarone was the only AAD to show a (non-significant) trend towards reducing the odds of mortality with a narrow CI (OR 0.85 [0.66, 1.09]). Withdrawals due to adverse events (AEs), incidence of serious adverse events (SAEs) and treatment discontinuation were increased following active treatment compared with control, with few significant differences reported between active treatments. Data for other morbidity outcomes such as cardiovascular mortality, hospitalizations or persistence/compliance and health-related quality of life (HRQoL) were limited and meta-analyses were not possible for these outcomes. CONCLUSION: The current meta-analysis confirms the efficacy of AADs in preventing AF recurrence, although their use is associated with a greater incidence of AEs and treatment discontinuation. Further RCTs are required to establish the benefit of AADs in the management of both morbidity outcomes and HRQoL.

Treatments for chronic myeloid leukemia: a qualitative systematic review.

BACKGROUND: Chronic myeloid leukemia (CML) is a myeloproliferative disorder of blood stem cells. The tyrosine kinase inhibitor (TKI) imatinib was the first targeted therapy licensed for patients with chronic-phase CML, and its introduction was associated with substantial improvements in response and survival compared with previous therapies. Clinical trial data are now available for the second-generation TKIs (nilotinib, dasatinib, and bosutinib) in the first-, second-, and third-line settings. A qualitative systematic review was conducted to qualitatively compare the clinical effectiveness, safety, and effect on quality of life of TKIs for the management of chronic-, accelerated-, or blast-phase CML patients. METHODS: Included studies were identified through a search of electronic databases in September 2011, relevant conference proceedings and the grey literature. RESULTS: In the first-line setting, the long-term efficacy (up to 8 years) of imatinib has been confirmed in a single randomized controlled trial (International Randomized Study of Interferon [IRIS]). All second-generation TKIs reported lower rates of transformation, and comparable or superior complete cytogenetic response (CCyR), major molecular response (MMR), and complete molecular response rates compared with imatinib by 2-year follow-up. Each of the second-generation TKIs was associated with a distinct adverse-event profile. Bosutinib was the only second-generation TKI to report quality-of-life data (no significant difference compared with imatinib treatment). Data in the second- and third-line setting confirmed the efficacy of the second-generation TKIs in either imatinib-resistant or -intolerant patients, as measured by CCyR and MMR rates. CONCLUSION: Data from first-line randomized controlled trials reporting up to 2-year follow-up indicate superior response rates of the second-generation TKIs compared with imatinib. Current evidence from single-arm studies in the second-line setting confirm that nilotinib, dasatinib, and bosutinib are valuable treatment options for the significant subgroup of patients who are intolerant or resistant to imatinib treatment.

The role of Bach1 in ultraviolet A-mediated human heme oxygenase 1 regulation in human skin fibroblasts.

Up-regulation of heme oxygenase 1 (HO-1) by ultraviolet A (UVA; 320-380 nm) irradiation of human skin cells protects them against oxidative stress. The role of Nrf2 in up-regulation of HO-1 and other phase II genes is well established. The mechanism underlying Bach1-mediated HO-1 repression is less well understood although cellular localization seems to be crucial. Because prolonged HO-1 overexpression is likely to be detrimental, it is crucial that activation of the gene is transient. We now show that UVA irradiation of cultured human skin fibroblasts enhances accumulation of Bach1 mRNA and protein severalfold. Endogenous Bach1 protein accumulates in the nucleus after 8h and may occupy MARE sites after HO-1 activation thus providing a compensatory mechanism to control HO-1 overexpression. Overexpression of Bach1, together with MafK, represses basal and UVA-mediated HO-1 protein expression, whereas silencing of the Bach1 gene by Bach1-specific siRNAs causes robust enhancement of constitutive HO-1 levels. UVA treatment of cells in which Bach1 has been silenced leads to higher levels of induction of the HO-1 protein. Although Bach1 protein is exported from the nucleus 12h after UVA irradiation, the release of free cellular heme from microsomal heme-containing proteins is immediate rather than delayed. Although heme does promote the export of Bach1 via the Crm1/exportin 1 pathway and is involved in the delayed UVA-mediated export of the protein, it is not clear how this occurs.

A systematic review and mixed treatment comparison of the efficacy of pharmacological treatments for fibromyalgia.

OBJECTIVES: To review the literature on pharmacological treatments for fibromyalgia. METHODS: Relative efficacy was estimated in terms of outcome measures highlighted by the Outcome Measures in Rheumatology Network using a Bayesian mixed treatment comparison (MTC) meta-analysis. Randomized controlled trials reporting treatments for fibromyalgia were identified by systematically reviewing electronic databases (Cochrane Library, Medline, EMBASE; accessed February 2008) and conducting manual bibliographic searches. RESULTS: Forty-five randomized controlled trials met the prespecified inclusion criteria for the systematic review. There were limited robust clinical data for some therapeutic classes (tricyclic antidepressants, analgesics, sedative hypnotics, monoamine oxidase inhibitors) and only 21 studies met the more stringent criteria for inclusion in the MTC. The majority of studies included in the MTC assessed the anticonvulsant pregabalin (n = 5) or the serotonin norepinephrine reuptake inhibitors (SNRIs) duloxetine (n = 3) and milnacipran (n = 3). Licensed doses of pregabalin and duloxetine were significantly (P < 0.05) more efficacious than placebo in terms of absolute reduction in pain, number of "responders" (≥30% reduction in pain), or change in Fibromyalgia Impact Questionnaire score (pregabalin 450 mg/d only). There was no significant difference between licensed doses of pregabalin and duloxetine for these outcomes. However licensed doses of pregabalin produced significantly greater improvements in sleep compared with milnacipran (as measured by Medical Outcomes Study Sleep Scale). CONCLUSIONS: The current study confirms the therapeutic efficacy of pregabalin and the SNRIs, duloxetine and milnacipran, in the treatment of fibromyalgia. Given their different modes of action, combination therapy with pregabalin plus an SNRI should be investigated in future research.

B-vitamins and fatty acids in the prevention and treatment of Alzheimer's disease and dementia: a systematic review.

The increasing worldwide prevalence of dementia is a major public health concern. Findings from some epidemiological studies suggest that diet and nutrition may be important modifiable risk factors for development of dementia. In order to evaluate the strength of the available evidence of an association of dietary factors with dementia including Alzheimer's disease (AD), we systematically searched relevant publication databases and hand-searched bibliographies up to end July 2007. We included prospective cohort studies which evaluated the association of nutrient levels with the risk of developing dementia and randomized intervention studies examining the treatment effect of nutrient supplementation on cognitive function. One hundred and sixty studies, comprising ninety one prospective cohort studies and sixty nine intervention studies, met the pre-specified inclusion criteria. Of these, thirty-three studies (19 cohort and 14 randomized controlled trials) investigated the effects of folate, B-vitamins, and levels of homocysteine (a biomarker modifiable through B-vitamin supplementation) or fish/fatty acids and are the focus of the present report. Some observational cohort studies indicated that higher dietary intake or elevated serum levels of folate and fish/fatty acids and low serum levels of homocysteine were associated with a reduced risk of incident AD and dementia, while other studies reported no association. The results of intervention studies examining the effects of folic acid or fatty acid supplementation on cognitive function are inconsistent. In summary, the available evidence is insufficient to draw definitive conclusions on the association of B vitamins and fatty acids with cognitive decline or dementia, and further long-term trials are required.

Attachment of human primary osteoblast cells to modified polyethylene surfaces.

Ultra-high-molecular-weight polyethylene (UHMWPE) has a long history of use in medical devices, primarily for articulating surfaces due to its inherent low surface energy which limits tissue integration. To widen the applications of UHMWPE, the surface energy can be increased. The increase in surface energy would improve the adsorption of proteins and attachment of cells to allow tissue integration, thereby allowing UHMWPE to potentially be used for a wider range of implants. The attachment and function of human primary osteoblast-like (HOB) cells to surfaces of UHMWPE with various levels of incorporated surface oxygen have been investigated. The surface modification of the UHMWPE was produced by exposure to a UV/ozone treatment. The resulting surface chemistry was studied using X-ray photoelectron spectroscopy (XPS), and the topography and surface structure were probed by atomic force microscopy (AFM) and scanning electron microscopy (SEM), which showed an increase in surface oxygen from 11 to 26 atom % with no significant change to the surface topography. The absolute root mean square roughness of both untreated and UV/ozone-treated surfaces was within 350-450 nm, and the water contact angles decreased with increasing oxygen incorporation, i.e., showing an increase in surface hydrophilicity. Cell attachment and functionality were assessed over a 21 day period for each cell-surface combination studied; these were performed using SEM and the alamarBlue assay to study cell attachment and proliferation and energy-dispersive X-ray (EDX) analysis to confirm extracellular mineral deposits, and total protein assay to examine the intra- and extracellular protein expressed by the cells. HOB cells cultured for 21 days on the modified UHMWPE surfaces with 19 and 26 atom % oxygen incorporated showed significantly higher cell densities compared to cells cultured on tissue culture polystyrene (TCPS) from day 3 onward. This indicated that the cells attached and proliferated more readily on the UV/ozone-treated UHMWPE surfaces than on untreated UHMWPE and TCPS surfaces. Contact guidance of the cells was observed on the UHMWPE surfaces by both SEM and AFM. Scanning electron micrographs showed that the cells were confluent on the modified UHMWPE surfaces by day 10, which led to visible layering of the cells by day 21, an indicator of nodule formation. In vitro mineralization of the extracellular matrix expressed by the HOB cells on the modified UHMWPE surfaces was confirmed by SEM and EDX analysis; spherulite structures were observed near cell protrusions by day 21. EDX analysis confirmed the spherulites to contain calcium and phosphorus, the major constituents in calcium phosphate apatite, the mineral phase of bone. Overall cell attachment, functionality, and mineralization were found to be enhanced on the UV/ozone-modified UHMWPE surfaces, demonstrating the importance of optimizing the surface chemistry for primary HOB cells.

DNA double-strand breaks form in bystander cells after microbeam irradiation of three-dimensional human tissue models.

The "radiation-induced bystander effect," in which irradiated cells can induce genomic instability in unirradiated neighboring cells, has important implications for cancer radiotherapy and diagnostic radiology as well as for human health in general. Although the mechanisms of this effect remain to be elucidated, we reported previously that DNA double-strand breaks (DSBs), directly measured by gamma-H2AX focus formation assay, are induced in bystander cultured cells. To overcome the deficiencies of cultured cell studies, we examined alpha-particle microbeam irradiation-induced bystander effects in human tissue models, which preserve the three-dimensional geometric arrangement and communication of cells present in tissues in vivo. In marked contrast to DNA DSB dynamics in irradiated cells, in which maximal DSB formation is seen 30 min after irradiation, the incidence of DSBs in bystander cells reached a maximum by 12 to 48 h after irradiation, gradually decreasing over the 7-day time course. At the maxima, 40% to 60% of bystander cells were affected, a 4- to 6-fold increase over controls. These increases in bystander DSB formation were followed by increased levels of apoptosis and micronucleus formation, by loss of nuclear DNA methylation, and by an increased fraction of senescent cells. These findings show the involvement of DNA DSBs in tissue bystander responses and support the notion that bystander DNA DSBs are precursors to widespread downstream effects in human tissues. Bystander cells exhibiting postirradiation signs of genomic instability may be more prone than unaffected cells to become cancerous. Thus, this study points to the importance of considering the indirect biological effects of radiation in cancer risk assessment.

Biological effects in unirradiated human tissue induced by radiation damage up to 1 mm away.

A central tenet in understanding the biological effects of ionizing radiation has been that the initially affected cells were directly damaged by the radiation. By contrast, evidence has emerged concerning "bystander" responses involving damage to nearby cells that were not themselves directly traversed by the radiation. These long-range effects are of interest both mechanistically and for assessing risks from low-dose exposures, where only a small proportion of cells are directly hit. Bystander effects have been observed largely by using single-cell in vitro systems that do not have realistic multicellular morphology; no studies have as yet been reported in three-dimensional, normal human tissue. Given that the bystander phenomenon must involve cell-to-cell interactions, the relevance of such single-cell in vitro studies is questionable, and thus the significance of bystander responses for human health has remained unclear. Here, we describe bystander responses in a three-dimensional, normal human-tissue system. Endpoints were induction of micronucleated and apoptotic cells. A charged-particle microbeam was used, allowing irradiation of cells in defined locations in the tissue yet guaranteeing that no cells located more than a few micrometers away receive any radiation exposure. Unirradiated cells up to 1 mm distant from irradiated cells showed a significant enhancement in effect over background, with an average increase in effect of 1.7-fold for micronuclei and 2.8-fold for apoptosis. The surprisingly long range of bystander signals in human tissue suggests that bystander responses may be important in extrapolating radiation risk estimates from epidemiologically accessible doses down to very low doses where nonhit bystander cells will predominate.

Combined haploinsufficiency for ATM and RAD9 as a factor in cell transformation, apoptosis, and DNA lesion repair dynamics.

Loss of function of oncogenes, tumor suppressor genes and DNA damage processing genes has been implicated in the development of many types of cancer, but for the vast majority of cases, there is no link to specific germ line mutations. In the last several years, heterozygosity leading to haploinsufficiency for proteins involved in DNA repair pathways was shown to play a role in genomic instability and carcinogenesis after DNA damage is induced. Because the effect of haploinsufficiency for one protein is relatively small, we hypothesize that predisposition to cancer could be a result of the additive effect of heterozygosity for two or more genes, critical for pathways that control DNA damage signaling, repair or apoptosis. To address this issue, primary mouse cells, haploinsufficient for one or two proteins, ATM and RAD9, related to the cellular response to DNA damage were examined. The results show that cells having low levels of both ATM and RAD9 proteins are more sensitive to transformation by radiation, have different DNA double-strand break repair dynamics and are less apoptotic when compared with wild-type controls or those cells haploinsufficient for only one of these proteins. Our conclusions are that under stress conditions, the efficiency and capacity for DNA repair mediated by the ATM/RAD9 cell signaling network depend on the abundance of both proteins and that, in general, DNA repair network efficiencies are genotype-dependent and can vary within a specific range.

Cricotiroidotomía y trauqueostomía en el tratamiento de la obstrucción aguda de la vías aéreas / Cricothyrotomy and tracheostomy in the treatment of acute air way obstruction

La obstrucción de las vías aéreas superiores es una verdadera catastrofe cuando ocurre en ausencia de los elementos indispensables para corregirlo inmediatamente, bien sea mediante medidas transitorias o definitivas. Este artículo describe paso a paso, las técnicas empleadas en la cricotiroidotomia con aguja y con bísturi y en la traqueostomia formal y de urgencia, que constituyen las formas más efecientes de establecer rapidamente la respiración en aquellos pacientes en quienes la naturaleza misma de la obstrucción no permite la intubación orotraqueal o nasotraqueal o hace inútil la realización de medidas mecáncias externas como maniobra de Heimlich.